Was actually thinking more a lizardman from a swampy area- think something like the Lousiana Bayou. I doubt he thinks of himself as being particularly evil, but I imagine a lot of others think he's quite vile. I've got a few ideas for magic involving severed heads, and I have this hilarious mental image of him doing a musical number in a shack in a swamp, where reanimated shrunken heads take the place of woodland creatures in a big parody of disney princess style musicals.

Anyway yeah, he'd probably be mostly self-interested, and if his goals happened to align with the goals of a good group, he'd happily work with them. I could see him being a sometimes ally, sometimes enemy that's super useful when he's on their side, but at the same time a dangerous foe when they oppose him.

I imagine that Desert Lizardfolk and Swamp Lizardfolk could just be different subraces. I can picture the desert ones being smaller and lighter coloured, while the swamp ones are larger than humans and often have dark green or even black coloration.

I mean in the desert in the real world, to my knowledge lizards tend to be small, while in swamps you get crocodiles. Kinda thinking along those lines.